Field
Surgical robots allow surgeons to operate on patients in a minimally invasive manner. The present application relates to surgical systems and methods, and more particularly to a hyperdexterous surgical system with one or more hyperdexterous surgical arms and one or more hyperdexterous surgical tools, and methods of operating the same.
Description of the Related Art
Currently, surgeons must select between discrete modes of minimally invasive surgery utilizing many techniques. Laparoscopic surgery generally falls in two categories: laparoscopic surgery with manual tools and laparoscopic surgery with robotic tools. In laparoscopic surgery using manual tools, procedures are typically performed through small incisions. The manual tools can be translated, rotated, and/or moved about a fulcrum. For manual tools that rotate about a fulcrum, the surgeon holds the handle of the tool. As the surgeon moves the handle in one direction, the distal end of the tool moves in another direction. The resulting motion of the distal end of the tool relative to the motion of the proximal end of the tool may not be natural, requiring the surgeon to practice the technique.
The motions of the laparoscopic tool are captured by a laparoscopic camera. The laparoscopic camera has a long shaft that is inserted into the body through an incision just like a manual tool. The laparoscopic camera is positioned to view the distal tips of the manual tools and captures the motion of the distal end of the tools. The display typically shows the motion of the tools relative to the frame of reference of the camera. For manual tools that rotate about a fulcrum, the tool moves in a polar coordinate system which may not be readily apparent based on the images of the laparoscopic camera.
Another mode of laparoscopic surgery is robotic surgery. In on-market robotic surgical systems, a large robotic arm controls a robotic tool. The tool is inserted into a small incision. The distal end of the robotic tool typically includes an end effector (e.g., a grasper, stapler, etc.) for performing a procedure within the body of the patient. The end effector is translated in space, within the constraints of the capabilities of the robotic arm. The surgeon typically controls the robotic arm from an immersive console that is remote from the patient. The robotic tool is configured to do certain surgical tasks well, but is not well-suited for other surgical tasks.
In on-market surgical robotic systems, the motions of the robotic tool are generally captured by a robotic camera. The motions of the robotic camera are controlled by a robotic arm, also under control of the surgeon just like the robotic arms controlling the robotic tools. The surgeon can map the movements of his hand to the movement of the robotic tool in the frame of reference of the camera. The motions of the surgeon's hands are mapped to the distal end effectors of the robotic tools within the frame of reference of the robotic camera. The frame of reference is therefore limited to the view provided by the camera. The display typically shows the motion of the distal end of the robotic tools relative to the frame of reference of the camera. The surgeon must therefore create a mental model of the anatomy with the limited information provided by the camera to control the robotic tools as desired for a particular task. Due to his remote location, the surgeon cannot acquire additional views of the patient in order to augment his understanding of the surgical space. This mode of operation is limiting for large motions or motions where it is more natural to move with respect to a frame of reference outside the body of the patient. Therefore, controlling the distal tips of the robotic tools relative to the robotic camera frame of reference makes some aspects of the surgical procedure more natural as compared to laparoscopic surgery using manual tools. For example it may be easier to manipulate a needle holder tool in a suturing task. However, the limited frame of reference of the robotic camera makes some other aspects of the surgery less natural. For example, making large movements from one quadrant of the abdomen to another, especially motions that involve the camera sweeping through an arc that includes the midline of the patient, are very challenging. These same motions can be accomplished in a natural manner with manual tools from a frame of reference external to the patient's body.
The on-market systems have complex mechanisms controlling the tool, for instance controlling the rotation and translation of the tool. In some current robotic systems, translation of the tool is achieved using a complex and bulky series of nesting linear slides. In order to make the full length of the tool shaft available for surgery, the slides are attached to the extreme proximal end of the tool. As a result, in any condition except full extension of the tool into the body, the translation mechanism extends away from the patient's body. In this position, the translation mechanism is subject to interference with other components of the robotic arm or other robotic arms. The size of the rotation and translation mechanism does not allow close positioning of adjacent robotic arms, so in some cases, robotic tools are placed further apart. The translation mechanism imparts a high inertial load on the robotic arm when the tool moves through pitch and yaw, thereby necessitating a larger, more powerful arm. The rotation and translation mechanisms add weight to the distal end of the robotic arm. The linking segments and the motors to control the linking segments must therefore be larger in order to move the complex rotation and translation mechanisms controlling the robotic tool. Each additional segment and each additional motor add weight that compounds the problem. The distal end of the robotic arm is heavy and has to be supported by increasingly more powerful proximal joints to maintain adequate level of stiffness.
The robotic arms therefore are bulky and occupy the space surrounding the patient. In cases where multiple robotic arms used to perform a surgical procedure, the arms must be carefully coordinated to avoid collisions. Further, many additional steps are taken to reposition the robotic arm to avoid collisions between components of the robotic arm. Further, due to the angle of insertion, the size and design of the robotic arms and tools, and other factors, the robotic arm may be unable to reach certain locations, called dead zones. The large size of the robotic arm forces the surgical staff to plan the operation around the robotic arm. This leads to less flexibility and efficiency for surgical procedures. Additionally, on-market robotic arms are heavy. The design of the robotic systems requires specially designed operating arenas, already set up for the use of the robotic system. There is thus limited flexibility in the setup of the operating room.
The surgeon is located remotely from the patient when using on-market robotic surgical systems, often sitting or standing at a remote console. Typically, the surgeon views the surgery site and tools through a viewer which provides an immersive experience. In some cases, communication between the surgeon and the supporting staff is constrained or impeded due to the surgeon's position over the console. Teams that perform robotic surgery need to be highly trained and skilled since the surgeon is remote from the patient and unable to communicate with the staff directly. It takes months, in some cases years, of practice to achieve a high level of efficiency in situations where robotic surgery is performed. This makes it difficult for members of the team to be replaced. Additionally, from this remote location (at the console), the surgeon cannot simultaneously use manual tools while controlling the robot arm.
Some tasks such as executing large scale motion of the robotic tools from one surgical site to another surgical site in a patient's body become more difficult due to the interference of components of the robotic arms. Some tasks easily performed with manual tools are more complex or impossible to perform with robotic tools. For example, in some cases, the robot simply does not have an end effector capable of accomplishing the task. Some tasks requiring tactile feedback, such as palpation, cannot be done by the surgeon operating the robotic arm. Rather, the surgeon operating the robotic arm requires an assistant or a surgeon beside the operating table to assist in these types of tasks.
On-market robotic arms typically have two degrees of freedom. Typically, these two degrees of freedom come from a pitch mechanism and a roll mechanism. The robotic tool typically has four degrees of freedom. The robotic tool can typically translate and rotate. The robotic tool can typically pitch and yaw at the wrist. The on-market systems typically thus have six degrees of freedom including the degrees of freedom from the robotic arm and the robotic tool.
The translation mechanism used by some robotic arms cannot rotate about the shaft axis. To achieve rotation, these systems simply rotate just the tool shaft independently of the translation mechanism. The cables which articulate the end effector twist during rotation, thus causing friction and binding of the cables. This twisting causes a change of length in the cables which must be compensated for by elasticity or slack in the system. This twisting also causes a limitation on the range of rotation, typically limited to approximately +/−270° of rotation.
One drawback of the current modes of minimally invasive surgery discussed above is that they are discrete. In order for the surgeon to use manual tools at the operating table, he or she cannot be controlling the robotic arm at a remote console. In order for the surgeon to control the robotic arm at a remote console, he or she cannot be using manual tools at the operating table. The surgeon cannot simultaneously control both robotic tools and manual tools.
Another drawback of the current modes of minimally invasive surgery is that they provide limited information to the surgeon. Typically this information is limited to the view of a robotic camera. The surgeon is not provided with information about additional constraints, such as the location of the patient, surgeon, or tools relative to the image from the camera. The surgeon is not provided with information to understand the frame of reference of the camera without moving the tools and/or moving the robotic camera. By moving the tools and viewing the image, the surgeon can create a mental model of the work space inside the patient and the operating arena.
Another drawback with on-market robotic surgical systems is that they do not allow the surgeon the ability to reposition him or herself during surgery. The surgeon must remain at the immersive console to manipulate the robotic tools to perform a surgical task with the end effectors of the robotic tools.
Another drawback of on-market robotic surgical systems is that they are typically anchored to the ground and do not follow the orientation of the patient during the course of surgery. The position of the robotic arm and/or bed cannot be changed while the robotic arm is in use. Typically robotic arms are mounted to a horizontal level surface (e.g., anchored to the floor) and the patient is placed on a horizontal level surface (e.g., bed). In some surgeries, it may be advantageous to angle (e.g., tilt) the body of the patient relative to the horizontal surface (e.g., lowering the head of the patient to have internal organs shift toward the patient's head) based on the surgery to be performed.
Another drawback with on-market robotic arms is that accessing the workspace may require the robotic arms to move through a very large range of motion. The movement may be limited when multiple robotic arms are used for a single surgery. The chances of collision between the robotic arms or components of a single robotic arm increases. The challenge is to maximize the work space inside the body while maximizing the free space outside of the patient, while also keeping the robotic system small and compact.